The Third Generation Partnership Project (3GPP) unites six telecommunications standards bodies, known as “Organizational Partners,” and provides their members with a stable environment to produce the highly successful Reports and Specifications that define 3GPP technologies. A mobile device, also called a User Equipment (UE), may operate in a wireless communication network that provides high-speed data and/or voice communications. The wireless communication networks may implement circuit-switched (CS) and/or packet-switched (PS) communication protocols to provide various services. For example, the UE may operate in accordance with one or more radio technology such as Universal Terrestrial Radio Access (UTRA), Evolved UTRA (E-UTRA), and GSM as part of an Universal Mobile Telecommunication System (UMTS). UTRA, E-UTRA, GSM, UMTS and LTE (Long Term Evolution) are described in specification documents from an organization named “3rd Generation Partnership Project” (3GPP). These various radio technologies and standards are known in the art.
The Evolved Packet Core (EPC) is the latest evolution of the 3GPP core network architecture first introduced in Release 8 of the standard. In EPC, the user data and the signaling data are separated into the user plane and the control plane. The EPC is composed of four basic network elements: the Serving Gateway (SGW), the Packet Data Network Gateway (PDN GW or PGW), the Mobility Management Entity (MME), and the Home Subscriber Server (HSS). The EPC is connected to external networks, which can include the IP Multimedia Core Network Subsystem (IMS).
Incorporated herein by reference is 3GPP specifications ETSI TS 123 401 LTE; General Packet Radio Service (GPRS) Enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Access (3GPP TS 23.401).